DARPA seeks ways to rebuild space junk

The Defense Department’s research and development shop is developing a new method to get more detailed images of orbiting satellites.

Better imaging would allow the DOD to select dead or deactivated spacecraft for a related program that would use robots to build new satellites in orbit from parts salvaged from deactivated craft.

The primary goal of the Defense Advanced Research Project Agency’s Galileo program is to get better and timely images of objects in geosynchronous orbit from the ground, said program manager Air Force Lt. Col. Travis Blake.

But Galileo is also intended to support the agency’s Phoenix program, which aims to salvage usable antennas and other components from retired satellites. Being able to image spacecraft is key to the planning aspect of the Phoenix program, Blake said.

The Phoenix program aims to save on the cost of launching new satellites when older ones have died by robotically removing and re-using space apertures and antennas from the old satellites.

The program plans to develop a new class of small "satlets," or nano satellites, that could "ride along" with a commercial satellite and then be “attached to the antenna of a non-functional cooperating satellite robotically, essentially creating a new space system,” DARPA said.

The main challenge Galileo faces is that using ground-based telescopes to get detailed views of object in geosynchronous orbit (22,000 miles) would require mirrors that are too large to build or use efficiently. Instead, DARPA is working on a different imaging technique, interferometric imaging, to get detailed images.

Astronomers use interferometry techniques to track and image objects in space with multiple telescopes. However, this process currently takes time and requires extensive infrastructure such as long light tubes, mirrors and other equipment that inhibits participating telescopes’ range of movement.

DARPA’s goal is to replace the light tubes with flexible fiber optic cable, which would allow telescopes to move more freely on multiple axes, which could significantly speed up the imaging of objects in orbit, Blake said.

Besides checking out non-functional satellites, another benefit of Galileo would be to allow satellite operators to determine if components such as solar panels have deployed properly, which could significantly help in resolving any problems that occur once a vehicle is deployed, he said.

DARPA currently plans to run Galileo in two phases. The first will look at proposals for advanced concepts in precision fiber optic control and mobile telescopes. Phase two will last longer and include development, fabrication and testing of systems and end with an imaging demonstration, Blake said.